Block printing machine



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Jan, 5, W37. F. G. ROTTMUND;

' BLOCK'PRINTING MACHINE 1 Filed ma 24, less I Y v M34121 w mp6,,

Patented Jan. 5, 1937 PATENT OFFICE BLOCK PRINTING MAGHIN E Fred G. Rottmund, Lancaster, Pa., assignor to Armstrong Cork Company, Lancaster, Ia., a corporation of Pennsylvania Application May 24, 1933, Serial No. 672,604

16 Claims.

This invention relates to the art of printing and more particularly to a printing machine of the flat-block type such for example as those used in printing linoleum and similar floor coverings; Printing machines of the flat-block type comprise generally a plurality of frame members carrying printing blocks, usually of wood, adapted to be reciprocated by suitable mechanism to impress a design upon a web of base material as it is conveyed intermittently through the machine over a supporting bed.

The mechanism employed for reciprocating each printing head comprises essentially a pair of driven cams engaged by cam rollers mounted for rotation on printing head slides secured to opposite ends of the printing head frame. The cams which act to raise and lower the printing heads are so shaped that the heads are held in raised position while paint is applied to the under side thereof "by means of a paint roll travelling in a paint carriage or trough which is intermittently moved longitudinally of the machine under the printing blocks. After the paint has been applied, the blocks descend into printing contact with the web of base material, and after printing the heads are elevated above the paint receiving position for latching and then descend into paint receiving position. I

The heads are raised above the paint receiving position so that they may be locked or latched in raised position and out of paint receiving or printing operation. The cams are provided with what is known in this art as a high block which is effective for raising the printing heads for latching. (The conventional printing head moving and latching mechanism is shown in Jones and Webster Patent No. 1,263,900 issued April 23, 1918.) In certain types of latching mechanisms, the latches are manually operated, while in rug printing machines the latches are either mechanically or electrically operated. In any event, in latching up it is necessary to use the high block in order to raise the printing head to a point where the latching mechanism is eifective and this has always been above the paint receiving position for the block in order to avoid more than one application of paint to a block.

The high blocks have generally been made of a special heat treated steel and inserted as a unit into the head raising cam. They have been the cause of considerable trouble due to shock and wear, and they prohibit rapid movement of the printing heads by setting up vibration in the printing blocks; the blocks must be at rest when the paint is applied to them in order that the few thousandths of an inch of paint be evenly applied.

In printing piece goods which have a repeat equivalent to the width of the individual printing blocks the individual printing heads employed normally descend into printing position upon each cycle of movement of the machine except in those instances where it is desired to hold the heads out of printing position while a defective section of base material is passing through the machine. Where the defect is less than the width of an individual head, the printing heads are sequentially latched up while the defective section is passing through the machine. Where the defect is relatively large it may be necessary to hold the individual blocks out of operation during two or more cycles of the machine. Since such defects are infrequent, it is apparent, therefore, that the high block unnecessarily raises each printing head and drops it many thousands of times during each working day. This results in a continual jarring or vibration of the whole machine and consequent wear. As mentioned above, the speed of the machines is also definitely limited by vibration. The high block has not been eliminated because it is necessary to latch the heads up a distance from the paint applying rolls in order that excess paint will not be applied to the printing block surface and no mechanism has heretofore been developed which would permit latching out of paint receiving position without the use of high blocks. If the heads were latched up in paint receiving position, the color applying roll would apply an excess of paint to the printing block surface which would result in an uneven paint surface on the printed material and defective printing due to block chokes, or if a head be so latched for a considerable number of cycles of the machine, such an excess of paint would be applied that dripping of the paint from the block to the previously decorated web surface would inevitably result.

It is an object of my invention to provide a mechanism suitable for raising the individual printing heads out of paint receiving position without the use of a high block whereby the speed of the machine may be greatly increased and vibration, shock and wear is decreased. The mechanism is simple to operate and permits a single operator to latch the individual heads sequentially, latching one head during each cycle of the machine, whereby the heads may be held out of printing operation while a defective piece of material passes intermittently through the machine.

Inorder that my invention may be more readily understood I will describe a present embodiment thereof in connection with the accompanying drawing, in which Figure 1 is a side elevation illustrating my head raising and latching mechanism applied to a conventional fiat-block machine, and

Figure 2 is a view partly in section and partly in elevation taken along the line 11-11 of Figure 1 with parts of the printing head slide mechanism removed for sake of clarity of illustration of the latching and head raising mechanism.

In Figure 1 there is shown in chain lines two 'heads of a conventional flat-block printing machine, one of which is illustrated as being in paint receiving position, and the other is latched out of paint receiving or printing operation. The machine illustrated comprises printing blocks 2 supported by printing heads generally indicated by 3 which are provided with head slides 4 operating in guides 5 secured to longitudinal members 6 of the bed of the printing machine proper. The head slides 5 are provided with rollers I which normally follow cams 8 whereby the printing heads are raised and lowered in proper synchronism with paint carriages 9 positioned for movement beneath the printing blocks 2 in the conventional manner.

The head slides 5 are provided with adjustable latching teeth I adapted for engagement with latches II. The engagement or disengagement of the latches II with the teeth I0 determines whether the head is permitted to move and follow the motion determined by the cam 8 or remain in an elevated position with the followers I held above the path of the cams 8.

The cams S illustrated in Figure 1 are not provided with any point thereof which will raise the printing blocks 2 above the paint receiving position. It is necessary therefore to impart additional vertical movement to the latches II to effect this motion and to lift the followers I out of the path of the cams 8. This is effected by means of eccentrics I2 which support straps I3 supporting the latches II. The eccentrics I2 are keyed to and supported by shafts I4 which are rotated by handles I5. When the handles are in a vertical position as shown at the left of Figure l, the latches II are in lowered position, and when the handles are in horizontal position as shown at the right of Figure 1, the latches II are in elevated position holding the followers 1 free of the cams and holding the blocks 2 out of any possible engagement with the paint applying mechanism.

My latching mechanism may be operated to latch up the printing heads at any time that the follower 'I is traversing the circular part of the cam 8 (shown in Figure 1 in uppermost position). A locking pin 16 being disengaged, the handles may be rotated clock-wise as viewed in Figure 1 releasing the pressure of an adjusting screw I1 upon a spring I8 secured to the latch thereby permitting the latch to swing about the eccentric I2 in a clock-wise direction by virtue of pressure applied by a spring I9 secured to a bracket H. The latch being in lowered position during the initial movement of the handle I5 from its upright position, it is free to slide under the tooth I0 at any time when the follower I is on the circular part of the cam 8. Immediately upon the latch I I being under the tooth l0, the weight of the head 3 may be taken by the latches, either by the continued downward motion of the handle I5, which operates to rotate the eccentrics I2, or by the cam 8 rotating to a position where it no longer supports the follower 'I. It is apparent, therefore, that the head is safely under control and cannot crash down into the paint applying mechanism or onto the machine once the latch has swung under the tooth ID. The latch is retained in such position by the bias of the spring l9 and'by the chamfer on the tooth l0. Having snapped the latch under the tooth II], the operator merely rotates the handle to the point where the locking pin I6 will hold it, snaps the pin in place, and thereby effectively holds the head out of engagement with any moving parts. The motion of the handle is effective for releasing the bias of the disengaging spring I8 and for rotating the eccentric I2 causing the latch II to move vertically after engagement with the tooth I0, whereby the head is elevated above the paint receiving position. Duplicate parts being present on opposite sides of the machine, the same action takes place on each end of the head 3.

In order to insure that the latch will not be elevated by the operator before proper engagement is had between the latch engaging tooth I0 and the latch I I and at the same time to permit the operator to place the latch into position for automatic engagement with the latching tooth when the head is in paint applying position, I provide a detent 22 into which the locking pin I6 may be urged. A plate 23 attached to the head slide 4 serves as a guide to direct the latch II into engagement with the tooth I0 and prevents the latch from fouling the adjustable latch engaging tooth mechanism. When the head is in lowered position, the handle l5 may be moved until the locking pin I6 engages the detent 22, thus causing the latch II to move to the left (Figure 1) and engage the plate 23 being yieldingly urged thereagainst by the engaging spring l9. When the head is elevated and the cam follower engages the circular part of the cam, the spring I9 urges the latch II under the tooth I0 and the head may then be elevated out of paint receiving position.

To place a head in operation, the locking pin is withdrawn (right hand side of Figure 1) and the handle rotated in a counter-clock-wise direction. The adjusting screw I! will engage the disengaging spring I8 and bias it to snap the latch out of engagement with the tooth III immediately that the weight of the head has been taken by the cam 8 engaging the follower I and the tooth I i] has been raised an amount sufficient for the chamfered tooth and latch to clear each other. It is apparent therefore that the handles I5 may be turned and set for disengagement of the heads without reference to the position of the cams 8. The operator need not wait as with former devices; my mechanism permits the head to unlatch only when it is safe to do so, and then it is automatic if the handles are set for disengagement. The engaging spring I9 is stronger than the disengaging spring I8 or is biased to exert a greater force when the latch is in disengaged position. This can be accomplished either by proportioning of the springs or by the extent to which the springs are compressed.

An adjusting screw 20 piercing the bracket 2| limits the outward swing of the latch II in order to insure minimum motion of the latch and a quick action when the engaging spring I9 becomes effective.

While I have described and illustrated certain preferred embodiments of my invention, it will be understood that the invention may be otherwise embodied and practiced within the scope of the following claims.

I claim:

1. In a fiat block printing machine having a printing head, latching means for said head, a bearing about which said latching means is rotatable and means for imparting vertical motion to said bearing whereby said head is elevated out of operating position.

2. In a fiat block printing machine, the combination of a printing head mounted upon a carrier for reciprocable motion into and out of paint applying position, driving means for imparting motion to said printing head through said carrier and elevating means engaging said carrier and adapted upon movement to impart vertical motion to move said carrier out of engagement With said driving means, and means for imparting motion to the elevating means.

3. In a flat block printing machine, the combination of a printing head mounted upon a carrier for reciprocable motion into and out of paint applying position, driving means including a cam, a cam follower mounted upon said carrier and adapted to coact with said cam to impart reciprocable motion to said printing head, and means engaging said carrier and adapted upon movement to impart vertical motion to said carrier to move said cam follower out of operative relationship with said cam, and means for imparting motion to the carrier engaging means.

4. In a fiat block printing machine having a printing head, latching means for said head comprising a latch, means for supporing said latch, means for urging said latch into operative position and means for imparting vertical motion to said latch support.

5. In a flat block printing machine, a printing head, means for reciprocating said head, latching means for said head comprising a rotatable latch, a support for said latch, means for urging said latch into engagement with said head, means for imparting vertical motion to said latch support after said latch has engaged said head and means for automatically disengaging said latch from said head when said head and said reciprocating means are in operative relationship.

6. In a flat block printing machine having a printing head reciprocable into and out of paint applying position, latching means for holding said printing head out of paint applying operation and means for imparting motion to said latching means to raise said head out of paint receiving position.

'7. In a flat block printing machine having a printing head, means for reciprocating said head, latching means for holding said head out of reciprocatory movement and means for imparting motion to said latching means to move said head out of operative relationship with said reciprocating means.

8. In a flat block printing machine, the combination of a printing head mounted upon a carrier for reciprocable motion into and out of paint applying position, driving means effective for raising said printing head from paint applying position to paint receiving position, latch engaging means on said carrier, a latch, means for moving said latch into engagement with said engaging means and means for imparting motion to said latch to raise said head out of paint receiving position.

9. In a fiat block printing machine, a printing head mounted upon head slides, a cam operating on said slides to reciprocate said head, latch engaging means for said slides, latches mounted on opposite sides of said machine for engagement with said engaging means, a shaft connecting said latches and means for imparting vertical motion to said latches through said shaft to elevate said head to a position above the highest point imparted by said reciprocating means.

10. In a flat block printing machine, the combination of a printing head mounted upon a carrier, driving means including a cam for raising said head to paint receiving position, latch engaging means on said carrier, a latch engageable with said engaging means and means for imparting motion to said latch to elevate said head to a position above the highest point imparted by said cam.

11. In a flat block printing machine, a printing unit including a printing head, means for reciprocating the head, elevating means engageable with the printing unit and adapted upon movement to elevate the head to a position above the highest point imparted by the reciprocating means and means for imparting motion to the elevating means.

12. In a fiat block printing machine, a printing unit including a printing head, driving means for vertically reciprocating the head, elevating means engageable with the printing unit and adapted upon movement to impart vertical motion to the head additional to that imparted by the reciprocating means and means for imparting motion to the elevating means.

13. In a flat block printing machine, the combination of a printing head mounted upon a carrier for reciprocable motion into and out of paint receiving position, an eccentric, latch engaging means on the carrier, a latch including a portion forming an eccentric strap for the eccentric, the latch being engageable with the latch engaging means, and means for imparting rotative motion to the eccentric to cause the latch to engage the latch engaging means and move the head above paint receiving position.

14. In a flat block printing machine having a printing unit, including a printing head, driving means for reciprocating the head, latch engaging means on the printing unit, latching means including a latch and an eccentric support for the latch, means for imparting rotary motion to the eccentric to cause the latch, through the latch engaging means, to raise the head out of operative relationship with the driving means and to return the head into operative relationship with the driving means, and biased means for automatically disengaging said latch When the head and the driving means are in operative relationship.

15. A latching device for a printing head of a flat block printing machine comprising a latch engaging member adapted to be positioned on the head mechanism, a latch engageable with the member, a rotatable eccentric support for the latch, and means for rotating the eccentric support to impart vertical motion to the latch to elevate the latch engaging member and its associated mechanism.

16. A latching device for a printing head of a flat block printing machine comprising a latch engaging member adapted to be positioned on the head mechanism, a latch engageable with the latch engaging member and adapted upon motion to elevate said head mechanism, and means for imparting motion to the latch.

FRED G. ROT'IMUND. 

